split handlers.py into handlers/ package

- _helpers.py: CSRF, FTS sanitizer, pagination, response helpers, tag helpers
- search.py: BM25 + hybrid search, trusted/remote result rendering
- pages.py: add/edit/delete/bulk/bookmark handlers
- subscriptions.py: sync, share preview, API sites, subscription CRUD
- customize.py: settings form, about page
- tags.py: tag list and tag browse handlers
- data.py: export, import, semantic reindex handlers
- __init__.py: dispatch, re-exports, forum_plugin, _request_local

All 58 external symbols re-exported. No changes to app.py, conftest.py,
or any test file.

handlers/data.py

@@ -0,0 +1,125 @@
+import json
+import threading
+
+from db import get_db, return_db, get_setting, set_setting, index_url
+from templates import esc
+from ._helpers import _respond, _json_response, _redirect, _csrf_field
+
+MAX_EXPORT = 10000
+_reindex_thread = None
+
+
+def handle_export(query=None):
+    try:
+        batch = int((query or {}).get("batch", ["0"])[0])
+    except (TypeError, ValueError):
+        batch = 0
+    db = get_db()
+    try:
+        rows = db.execute(
+            "SELECT url, title, note FROM pages ORDER BY id LIMIT ? OFFSET ?",
+            (MAX_EXPORT, batch * MAX_EXPORT),
+        ).fetchall()
+    finally:
+        return_db(db)
+    data = [{"url": r["url"], "title": r["title"], "note": r["note"]} for r in rows]
+    return _json_response(data, headers={"Content-Disposition": "attachment; filename=tinyweb-export.json"})
+
+
+def handle_import_form(msg=""):
+    return _respond(
+        f"<h1>import</h1>"
+        f"<p>Paste the contents of a tinyweb export file (JSON).</p>"
+        f'<form method="post" action="/import">'
+        f'{_csrf_field()}'
+        f'<textarea name="data" rows="12" cols="60" placeholder=\'[{{"url": "...", "note": "..."}}]\'></textarea><br><br>'
+        f'<button type="submit">import</button>'
+        f"</form>"
+        f"<p>{msg}</p>"
+        f'<a href="/pages">back</a>'
+    )
+
+
+def handle_import_submit(body):
+    raw = body.get("data", [""])[0].strip()
+    if not raw:
+        return handle_import_form("Paste JSON data.")
+    try:
+        data = json.loads(raw)
+    except json.JSONDecodeError:
+        return handle_import_form("Invalid JSON.")
+    if not isinstance(data, list):
+        return handle_import_form("Expected a JSON array.")
+
+    MAX_IMPORT = 100
+    if len(data) > MAX_IMPORT:
+        return handle_import_form(f"Too many entries. Maximum is {MAX_IMPORT}.")
+
+    imported = 0
+    errors = 0
+    for entry in data:
+        url = entry.get("url", "").strip()
+        note = entry.get("note", "").strip()
+        if not url:
+            continue
+        try:
+            index_url(url, note)
+            imported += 1
+        except Exception:
+            errors += 1
+
+    return handle_import_form(f"Imported {imported} page(s). {errors} error(s).")
+
+
+def handle_reindex_form():
+    if get_setting("semantic_search", "0") != "1":
+        return _respond(
+            f"<h2>semantic search index</h2>"
+            f"<p>Semantic search is disabled. Enable it in <a href=\"/style\">settings</a> to use embeddings.</p>"
+            f'<p><a href="/">back to search</a></p>'
+        )
+    db = get_db()
+    try:
+        total_pages = db.execute("SELECT count(*) FROM pages").fetchone()[0]
+        pages_with_chunks = db.execute(
+            "SELECT count(DISTINCT page_id) FROM chunks WHERE page_id IS NOT NULL"
+        ).fetchone()[0]
+    finally:
+        return_db(db)
+    progress = get_setting("reindex_progress", "")
+    status_html = ""
+    if progress:
+        status_html = f'<p class="meta">Reindex in progress: {esc(progress)}</p>'
+    elif _reindex_thread and _reindex_thread.is_alive():
+        status_html = '<p class="meta">Reindex running...</p>'
+    return _respond(
+        f"<h2>semantic search index</h2>"
+        f"<p>{pages_with_chunks} of {total_pages} pages have embeddings.</p>"
+        f'{status_html}'
+        f'<form method="post" action="/reindex">'
+        f'{_csrf_field()}'
+        f'<button type="submit">reindex all pages</button>'
+        f'</form>'
+        f'<p><a href="/">back to search</a></p>'
+    )
+
+
+def handle_reindex_submit(body):
+    global _reindex_thread
+    if _reindex_thread and _reindex_thread.is_alive():
+        return handle_reindex_form()
+
+    def _run():
+        try:
+            from embeddings import reindex_all
+            def progress(current, total):
+                set_setting("reindex_progress", f"{current}/{total}")
+            reindex_all(progress_callback=progress)
+        except Exception:
+            pass
+        finally:
+            set_setting("reindex_progress", "")
+
+    _reindex_thread = threading.Thread(target=_run, daemon=True)
+    _reindex_thread.start()
+    return _redirect("/reindex")